Since the first human genome sequence was published, thousands of people have submitted their DNA for scientific analysis. They made these donations anonymously—or so they thought. Now, using publicly available information, researchers found they could figure out the identities of 50 individuals who had loaned their genes to science. Their results, although not the names of the people, are in the journal Science. [Melissa Gymrek et al., Identifying Personal Genomes by Surname Inference]

Biomedical research depends on the participation of human subjects, and issues of privacy have always been a concern. When scientists share genomic data, they first strip away identifying information, like the individual’s name and date of birth. But is that really enough?

Researchers looked at a specific set of markers in genomes whose sequences were in a public database. And they found that by matching up these markers with sequences that people had submitted to genealogy web sites, they could identify some of the genome donors’ relatives and, with a bit more sleuthing, come up with their actual names.

Of course, many people now post online accounts of what’s on their minds or even on their menus. But even those who are relatively relaxed about their privacy might think twice about their genomes going public.